Liquid chromatography-mass spectrometry (HPLC-MS) has shown its power in metabolomic study.Due to the high dimension of the HPLC-MS data, many multivariate analysis techniques, such as principal component analysis, partial least-squares discriminant analysis, random forest and support vector machine, have been applied in processing the HPLC-MS data.Support vector machine (SVM) [1] is a very popular classification method based on the statistic theory.